People living with HIV infection have a higher chance of developing undernutrition than those who are not infected. HIV affects the nutritional status of these people in different ways. The effects of HIV may occur at different times during the course of their illness.

The following are typical adverse effects of HIV infection which may affect the person's nutritional status:

• Reducing food consumption because of appetite loss or anorexia
• Nausea
• Oral thrush
• Constipation
• Bloating or heartburn.

People with HIV also tend to have various oral conditions that can make it difficult for them to eat. Impact on nutritional status includes:

• Impaired nutrient absorption
• Increased energy needs because of fever
• Possible increase in the need for other nutrients because of symptoms such as anaemia
• HIV-associated wasting
• Changing body composition.